#75 DB Migration: IP Whitelist Table

Create database migration for IP whitelist table. Migration File: engine/migrations/sql/XXX_ip_whitelist_table.sql Table: ip_whitelist Columns: - id: uuid primary key - tenant_id: varchar(100) - ip_or_cidr: cidr (PostgreSQL native type) - description: varchar(255) - created_at: timestamp - created_by: uuid - expires_at: timestamp (nullable for permanent) - is_active: boolean default true Indexes: - idx_ip_whitelist_tenant_active - idx_ip_whitelist_cidr (using gist for network containment) Functions: - check_ip_whitelisted(tenant_id, ip_address) returns boolean With ultra attention to details and correctness. Before closing: write comment summarizing implementation with screenshot.